Twenty-two people died when Salman Abedi detonated a suicide bomb after an Ariane Grande concert on 22 May.

Lord Kerslake’s full review is set to be published in March.

Image copyrightGMCAImage caption Lord Kerslake is the former head of the civil service

The review was commissioned by Mayor Andy Burnham to assess Greater Manchester’s readiness for the attack and look at the response of the city’s agencies and emergency services.

More than 170 people, including young people who were at the concert, have participated in the review via a phone line set up by charity NSPCC.

The panel has also spoken to members of the emergency services and public bodies involved in the attack.

The progress report said more than 400 documents have been submitted and the panel is also looking into the role of both mainstream and social media.

Image copyrightGetty ImagesImage caption St Ann’s Square in Manchester became the focus of tributes after the attack

Lord Kerslake said bereaved families and those injured have been put “at the heart” of the report.

He said: “The panel wants to ensure that the ethos of putting families first isn’t lost following this tragedy or in the future, that’s why we are recommending Greater Manchester adopts the Charter for Families Bereaved through Public Tragedy introduced as part of the Right Reverend Jones report.”

He said the review has given everyone the chance to “share their experiences of that dreadful night and the days that followed”.

Mr Burnham has urged for public bodies in Greater Manchester to sign up to the charter and “provide their fullest cooperation” to the panel.

Previously, Bishop Jones said the charter compels public bodies to approach public inquiries and inquests in an “open, honest and transparent way”.